One problem though: Sometimes the color combination of the game over screen makes it impossible to read on a real vic.
RIght now char-color is just (background-color + 1 and 7). Tried this in VICE and on my S-Video-moded VIC and while sometimes difficult to read it was always distinguishable. I am open to suggestions how to improve this, however.
I noticed while showing the game around that some people can play this very naturally while other fail miserably. Some try to be as fast as possible, while others play it safe and their time runs out. It's hard to find the best middle ground. BTW: You get "42 minus 2x level" bonus time for each correct answer, so at the beginning you get 4/6 of a second for each correct answer. And from level 22 forward you actually loose time. I've never made it that far myself without trainer, though.
Although I used a machine-language joystick-routine at the last minute (I borrowed from "Programming the VIC"), it still plays best with keyboard.
The original browser game I based this on can be found at
http://www.colorrun.pl